AUTHOR=Braschi Giacomo , D’Alessandro Margherita , Gottardi Davide , Siroli Lorenzo , Patrignani Francesca , Lanciotti Rosalba 

TITLE=Effects of Sub-Lethal High Pressure Homogenization Treatment on the Adhesion Mechanisms and Stress Response Genes in Lactobacillus acidophilus 08

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.651711

DOI=10.3389/fmicb.2021.651711

ISSN=1664-302X

ABSTRACT=<p>Cell surface hydrophobicity (CSH) and adhesion are very important phenotypical traits for probiotics that confer them a competitive advantage for the resilience in the human gastrointestinal tract. This study was aimed to understand the effects over time of a 50 MPa hyperbaric treatment on the surface properties of <italic>Lactobacillus acidophilus</italic> 08 including CSH, autoaggregation, and <italic>in vitro</italic> adhesion (mucin layer and Caco-2 cells). Moreover, a link between the hurdle applied and the expression of genes involved in the general stress response (<italic>groEL</italic> and <italic>clpP</italic>) and adhesion processes (<italic>efTu</italic> and <italic>slpA</italic>) was evaluated. High pressure homogenization (HPH) at 50 MPa significantly increased the CSH percentage (H%), autoaggregation and <italic>in vitro</italic> adhesion on mucin of <italic>L. acidophilus</italic> 08 cells compared with the untreated cells. Moreover, the hyperbaric hurdle induced an upregulation of the stress response genes <italic>groEL</italic> and <italic>ef-TU</italic> together with a down regulation of the <italic>clpP</italic> and <italic>S-layer slpA</italic> genes. Looking at the protein profile, HPH-treatment showed an increase in the number or intensity of protein bands at high and low molecular weights.</p>